Release Candidate Firmware V1.21 RC4

[misk]

Oh Daaaaamnn the triggers are so *damn* on point now! Everything is tight and consistent as hell, even at higher tempi, with just autogate for triggers—no tricks required! Really, REALLY good job on that Mr. XOR! my more triggers expander just arrived so after i finish playing with it, i'll check out the other updates. Once again, THANKS!!